Observation: System Blue Magnetic Sensors
#9
(2019-07-13, 07:36)drossbach1 Wrote: I got the station from a prior owner and good friend who preferred that I adopt the trouble-shooting problems he was having (he did a nice job of assembly from what I could tell)....I don't know what user info is appropriate to post on the forum...Cutty, I'd be happy to provide any information you would like... do I e-mail? (my e-mail is xxxx@comcast.net).  I didn't mess with the credentials as I was hoping to convince Bill to take the station back if I got it fixed, but he prefers the present status-quo.  The station number is 1808, original user 1509.  It is definitely a Blue board set (and is so labelled although the boards are actually green in color) and it does not have the piggy-back voltage regulator board.  I jumpered the preamps when I used them with a set of 1.1 meter diameter 6 turn loops of #12 THHN (these still exist .... I built the loops when the ferrite antennas seemed insensitive).  I then removed the jumpers when I went back to the ferrites (with shielding added ...  I seem to have a strong AM station challenge locally - the board has the active filters installed and enabled),  The ferrites measure self-resonance at 1.1 MHz and read 15.3 mHy using a General Radio Bridge @ 1kHz.  The fact that "signals" didn't seem to change much between these configurations (I was monitoring with a Tek TDS 2024C 4-channel scope at the SMA ports)  is what provoked the bench testing.  The positive rail voltage was zero even though the LED indicated power.  Originally, all 3 H-Preamp channels were unpowered.  I messed with the RJ45 when the "A channel" exhibited intermittent output after fixing the power connections.  Is it possible to purchase only the pre-amp board?  I would love to populate a new one versus always wondering about the present board.  The New Mexico Sun is pretty warm.   Denny

MOD note:- emailed removed for privacy as this is on the public forum. Denny please use the PM or email option

Dear Denny,

that's right, we've had some problems with the boards for some time. The vias were not always perfectly made. The boards were marked as not sufficient. But the assembly company has ignored this mark. However, these are very few boards that have such vulnerabilities. In general, there are only about 2 out of 100 boards.

We always have the boards assembled together as a whole, one motherboard with the two preamplifier boards. Individual preamps are therefore not available. But I can send empty boards for the price of shipping as many as you like.

/Egon
Stations: 753, 762, 1403
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RE: Observation: System Blue Magnetic Sensors - by Egon - 2019-07-31, 22:29



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